Controller for mobile glow discharge systems



July 8, 1947. H. c. METTLER 2,423,814

CONTROLLER FOR MOBILE GLOW DISCHARGE SYSTEMS Filed May 8, 1944 INVENTOR. #44 6'. M5772 is BYQQQQVMW ATTOENEY Patente d July 8, 1947 CONTROLLER FOR MOBILE GLOW DISCHARGE SYSTEMS Hal C. Mettler, Alhambra, Califi, assignor of one;-

half to Lloyd Spencer, South Basadena, Qalif.

Application May 8, 1944, Serial No. 534,624

6 Glaims. 1

My invention relates to controllers for mobile glow discharge systems; that is, to devices for producing mobile or progressive illumination in so-called neon tubing so as to give the eiiect of writing. The present invention is a continuation in part of my copending application filed November 12', 1940, Serial Number 365,206, entitled LOW frequency mobile glow discharge system, which issued August 1, 1944 as Patent Number 2,354,696.

Among the objects of my invention are:

First, to provide a controller for mobile glow discharge systems wherein an auto-transformer of the carbon-brush type is employed to control the input voltage to limited current or neon transformers connected With a glow discha tube system of the type more fully disclosed in the above mentioned patent application.

Second, to provide a controller for mobile glow discharge systems which is inherently capable of controlling a large amount of electrical energy so that signs of substantial size may be operated;

Third, to provide a controller of this character which is capable of causing mobile glow discharge in a plurality of glow discharge tubes either simultaneously or in sequence.

Fourth, to provide a controller'of this character wherein several brush elements are caused to move in sequence from the zero end to the onehundred percent end of an auto-transformer and thereafter remain in electrical association with said one-hundred percent end until all brush elements are in contact therewith, whereby illumination may be caused to progress from one glow discharge system to a succeeding glow discharge system without observable break or hesitation or interruption in the writing effect thus produced.

Fifth, to provide a controller of this character wherein an auto-transformer is provided with .dual windings arranged so that brush elements may move continuously from a zero end to a onehundred percent end and return, several brush elements being employed and displaced in out-ofphase relation to produce a novel mobile efiect in associated mobile glow discharge tubing systems.

With the above and other objects in view, reference is directed to the accompanying drawings, in which:

Figure 1 is a diagrammatical view of a glow discharge tubing system adapted for operation by I my controller.

Figure 2 is a diagrammatical view of one form of my controller shown arranged to control sev- -eral glow discharge tubing systems simultaneously.

is essentially an auto-transformer in which, core is ring-shaped with a single torus winding Figure 3 is a diagrammatical view ofa modified form of my controller wherein several glow discharge tubing systems are controlled insequence.

Figure 4 is a diagrammatical view of another modified form ofmy controller wherein the illumination of several glow discharge tubing systems is caused to progress and recede in time displaced relation.

Figure 5 is a transverse sectional View of a neon tube employed in conjunction with my controller.

The controller herein employed is particularly designed for use in conjunction with the mobile glow discharge system described in the aforementioned patent applic t n, B e y, said system comprises one or more glow discharge tubes l, commonly designated neon tubes although they may contain any one of the several rare ases or mercury vapor. Th glow discharge tubes have end electrodes 2 and 3, and interm'ediate electrodes 4. The intermediate electrodes are connected through resistors '5' to ground, the end electrode 3 is connected directly to ground, while the, end electrode 2 is connected to one side of the secondary B a limited current or neon transformer I. The outer end of said secondary is grounded. The tubing is provided with a metal coating 8 along its back side which coating is grounded,

The primary 9 of the neon transformer is connected to a source of power supply through a controller indicated generally by l0 in Figure 1. The controller and ts asso ation w th the glQW dischar e tubing system is the subiec o this a p icaticn and con ists es entia l in a no e ly-arranged transformer with moving brushes and a drive means therefor. 7

With reference to Figure 2, a controller trans former 2| is shown. The controller transfo r 22 connected at its ends. to a source of low i equency current. A brush 2'3 and its supporting arm is mounted on a shaft. 24 driven by a motor 25. The brush is arranged to wipe around the winding 22. The shaft carries a slip ring 26 connected with the brush 23. A contact 21 rides on the slip ring. It should be noted that the contact 21 may revolve with the brush 2.3,.in

which case the .slip ring 26 is stationary. In addition to (the slip ring, the "shaft 24 drives a cam 28 which controls a switch 29 in series with the contact 21.

3 former 1 while the other end thereof is connected to a leg of the input line.

The connections are such that the potential across the primary 9 varies from zero to full line voltage as the brush 23 moves around the winding 22. The full or 100% end of the winding 22 is provided with a short contact strip 3| terminating adjacent the zero end of the winding. The cam 28 is so arranged that the switch 29 is opened as the brush 23 moves from the contact strip 3! to the zero end of the winding, thus avoiding shorting the auto-transformer.

The controller l may control several glow discharge systems of the type shown in Figure 1 by controlling several neon transformers as shown in Figure 2, in this case four glow discharge system are shown. As a consequence, illumination may be caused to progress in all systems simultaneously.

In the construction shown in Figure 2, the

transformer winding 22 occupies virtually the entire circumference of the transformer core; in Figure 3, however, is illustrated a modified arrangement wherein the extent of the winding is reduced. Thus, the controller transformer 4| shown in Figure 3 is provided with a winding 42 connected with an elongated contact segment 43 at its 100% end. Several brushes 44 are provided. These are arcuately displaced and connected to individual slip rings 45. Independent circuits are provided through contacts 45* and leads 46 to transformers l. A switch 41 is provided between the 100% or segment end of the winding 42 and the supply lead thereto. This switch is controlled by a cam 48.

All, or at least all but one, of the slip rings 45 include insulated segments 49 which differ in length in proportion to the circumferential displacement of the brushes 44 so that the ends of all slip rings provided with insulated segments are opposite the contacts 45 simultaneously with operation of the cam 48 to open the switch 41. The leading brush is at such time at the extremity of the contact segment 43 and about to move onto the .zero end of the winding. The auto-transformer 41 is opened by the switch 41 to permit movement of the leading brush onto the zero end of the winding, and the other brushesonto their respective insulated segments 49.

The circuit controlled by each brush 44 may include one or several limited current or neon transformers as in the case of the construction shown in Figure 2. The circumferential displacement of the several brushes are such that as one glow discharge tubing system becomes fully illuminated, glow discharge begins in the next system without break or pause. The brushes 44 may have limited arcuate adjustment relative to circuits each comprisin one or more neon transdischarge systems at different times; that is, as one system is at full brilliancy, another is writing and the third is unwriting. This arrangement is particularly effective to illuminate indirectly the letter of a sign by using a different color of light in each system. The colors blend from one to the other to produce a beautiful rainbow effect.

Although I have shown certain embodiments of my invention, I do not wish to be limited thereto, but desire to include in the scope of my invention th constructions, combinations, and arrangements substantially as set forth in the appended claims.

I claim:

1. In a mobile glow discharge system: a plurality of glow discharge tubing units, each unit including continuous external metallic elements forming with the gaseous content of said tubing a distributed capacity, a series of electrodes spaced along the length of said unit, resistors connected to the intermediate electrodes; a high potential, limited current transformer for each unit, each transformer including a secondary formers and corresponding glow discharge systems. Because of the spacing of the brushes 54, the illumination is caused to progress in the glow connected to the extreme electrodes of its unit and a primary connected to a source of commercial low frequency current; one end of the secondary of each transformer, said metallic elements and an end electrode of the corresponding unit being electrically connected and establishing a common potential, said resistance elements bridging between their respective electrodes and said common potential; an auto-transformer including a winding and at least one moving brush electrically connected with the primaries of said limited current transformers to cause the voltage thereacross to vary between a predetermined minimum and a predetermined maximum.

2. In a mobile glow discharge system: a plurality of glow discharge tubing units, each unit including continuous external metallic elements forming with the gaseous content of said tubing a distributed capacity, a series of electrodes spaced along the length of said unit, resistors connected to the intermediate electrodes; a high potential, limited current transformer for each unit, each transformer including a secondary connected to the extreme electrodes of its unit and a primary connected to a source of commercial low frequency current; one end of the secondary of each transformer, said metallic elements and an end electrode of the corresponding unit being electrically connected and establishing a common potential, said resistance elements bridging between their respective electrodes and-said common potential; an auto-transformer including a torus shaped core; an arcuate winding occupying a portion of said core, a contact segment continuing from one end of-said winding around said core, brushes adapted to rotate about said winding and contact segment in sequence, said winding and brushes connected with the primaries of said limited current transformers to cause the voltage across said primaries to vary in sequencefrom predetermined minimums to predetermined maximums as said brushes move incorporates a distributed capacity and resistance network between its ends to cause progressive ionization in said tubingunit as the input voltage across said unit from a low frequency source is varied, the combination of a controller for varying said input voltage, comprising: limited current transformers having secondaries connected across said tubing units; an auto-transformer including a winding and, at least one moving brush electrically connected with the Primaries of said limited current transformers, and means for driving said moving brush to cause the voltage thereacross to vary between a predetermined minimum and a predetermined maximum, thereby to cause a corresponding progression of ionization in said tubing units.

4. In a mobile glow discharge system, wherein each of a plurality of glow discharge tubing units incorporates a distributed capacity and resistance network between its ends to cause progressive ionization in said tubing unit as the input voltage across said unit from a low frequency source is varied, the combination of a controller for varying said input voltage, comprising: limited current transformers having secondaries connected across said tubing units; and an auto-transformer including a torus shaped core; an arcuate winding occupying a portion of said core, a contact segment continuing from one end of said winding around said core, brushes adapted to rotate about said winding and contact segment in sequence, said winding and brushes connected with the primaries of said limited current transformers to cause the voltage across said primaries to vary in sequence from predetermined minimfims to predetermined maximums as said brushes move toward and onto said contact segment, whereby illumination is caused to progress along said tubing units in corresponding sequence.

5. In a mobile glow discharge system, wherein each of a plurality of glow discharge tubing units incorporates a distributed capacity and resistance network between its ends to cause progressive ionization in said tubing unit as the input voltage across said unit from a low frequency source is varied, the combination of a controller for varying said input voltage, comprising: limited current transformers having secondaries connected across said tubing units; and a moving brush auto-transformer; a plurality of moving brushes thereon electrically connected to corresponding limited current transformers for controlling the voltage thereof; means for driving said brushes in a predetermined sequence to effect corresponding sequence in the progression of illumination in said tubing units.

6. In a mobile glow discharge system, wherein each of a plurality of glow discharge tubing units incorporates a distributed capacity and resistance network between its ends to cause progressive ionization in said tubing unit as the input voltage across said unit from a low frequency source is varied, the combination of a controller for varying said input voltage, comprising: limited current transformers having secondaries connected across said tubing units; an auto-transformer including a torus shaped core and a. pair of semi-circular windings each occupying approximately one-half the circumference of the core and wound in reverse relation to the other, said windings being joined at their extremities to form parallel coils; moving brushes adapted to rotate around said windings, said windings and brushes connected with corresponding limited current transformers to cause the voltage across their primaries to vary progressively from minimum to maximum and return, thereby to cause corresponding progression and regression of ionization in said tubing units, said brushes being displaced in their positions with respect to said windings whereby the cycles of progression and regression of ionization of said tubing units are correspondingly displaced.

HAL C. NIETTLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

